Yes, he can do that. Promotion is not a right. If you did something that caused the chain of command to lose trust in you they can stop you from attending the promotion board. The command will typically reevaluate the decision in 90 days in this situation. This gives them enough time to see if you have corrected the issue. For more information on this subject see AR 600-8-19.
You may also find this Q&A useful: Can my platoon sergeant take me off the promotion list?